Process of making 1-phenyl-benzanthrone compounds



Patented Nov. 1 9, 1929 UNITED STATES PATENT, OFFICE WILL? TBAUTNEB, BEBTHOLD STEIN, AND ROBERT IBEBLINEB, OF ELIBEBFELD, GER- MANY, ASSIGNORS TO GENERAL ANILINE WORKS, INC., OF NEW YORK, N. Y., A COR- PORATION OF DELAWARE PROCESS OF MAKING l-PHENYL-IBENZANTHBONE COMPOUNDS Io Drawing. Application filed September 1 6, 1926,. Serial No. 135,990, and in Germany November 23, 1925.

Our invention provides for a novel and convenient method of making l-phenyl-benzanthrone compounds.

7 We have shown in our co-pending application Serial No. 135,984 filed on even date, that cinnamio aldehyde compounds condense in nonalkaline medium-with anthrone compounds to form cinnamylidene-anthrones of the general formula:

OHCH=CHO We have further shown in our co-pending application Serial No. 135,989 filed on even date, that by heating these 'cinnamylidene- I anthrone compounds to tem eratures of about 250 C. an intramolecu ar condensation takes place with formation of novel l-phenyl-benzanthrone compounds of the probable formula: v

which are usually yellow colored, crystalline substances, dissolvingv in concentrated sulcedure also of advantage in certain instances to add to the reaction mixture an acidic condensing agent, or to perform the reaction in a high boiling solvent. As such acidic cond'ensing agents which were found particularly useful we might mention phosphorous oxychloride, zinc chloride, acetic anhydrid, etc. The l-phenyl-benzanthrone compounds obtained in this manner are substantially identical with those obtained by heating the melting at 181' 0., dissolving in concentrated sulfuric acid with a red color. It has I most probably the formula and is identical with'the 1-phenyl-benzanthrone obtained in Example 1 of our application Serial No. 135,989 of even date. The yield is about 30-35% of theory.

- Ewample 2.9.7 parts anthrone and 7 parts cinnamic aldehyde are heated to the boiling point with 3.5 parts alpha-chloronaphthalene in such a manner that-the water formed during the reaction is not returned to the reaction. The reaction is finished after about one hou'rs heating. The cold melt is then run into i about 18 parts alcohol. The 1 henyl-benzanj a non I I O I i throne formed se arates as ye ow needles; it is filtered off, was ed with alcohol and dried. It is identical withwthe product obtained in lillxample 1. The yield is about 30-35% of t e0 Example 3.5.2 arts alpha-hydroxy-anthroneof the'form a:

or of the isomeric formula: r

"it n 3.5 parts cinnamic aldehyde and 0.5 parts zinc chloride are gradually heated, whilst stirring, to about 280 C. 1 The reaction is interrupted .as-soon as a sam le of the melt dissolves in concentrated'sul ric acid with a reddish-' orange color, showing. strong fluorescence. The melt is then' stirred up with methanol whereby it solidifies. It is then crystallized from pyridine and yellow needles of l-phenylalpha-hydroxy-benzanthrone are obtained.

Ewample 4.A suspension of 19 parts anthrone, 14 parts cinnamic aldehyde, 2 parts potassium acetate and parts acetic anhydrid are heated in an open vessel until a temperature of about 290 C. is obtained. The melt is then stirred u with 150 parts hot alcohol,filtered ofi col the residue boiled up with diluted aqueous alcohol and the solidified resinous product rubbed on with acetone.

Yellow needles of l-phenyl-benzanthrone are so obtainedwith a yield of about Example 5.A mixture of 2.8 parts betachloro-anthrone of the formula:

' 1.8 parts cinnamic or of the isomeric formula:

aldehyde and 1.5 parts alpha-chloro-naphthalene are slowly heated,

-zanthrone com oun a little" hosphor'ous oxychloride is added drop by brought .tO iling temperature. The reaco and finally the reaction mass is tion 15 allowed to cool. as soon as a sample dissolves in concentrated sulfuric acid wlth the bluish-red, fluorescent color characteristic for the l-phenyl-beta-chloro-benzanthrone. I

The so obtained dark resinous roduct is rubbed on with methanol, it soli ifie's' after some standing. After extracting it with acetone light yellow needles of 1-phenyl-beta-,

chloro-benzanthrone are obtained with a yield of about 10-20% of theory. y We claim: 7

. 1. The process OfJIOdllCillg l-phenyl-ben- 'namic aldehyde to temperatures of about s which consists in heats which consists in heating mlxtures o anthrone compounds and cmnamic aldehyde in presence of an acidic concinnamic aldehyde in presence of an acidic.

condensing agent and a high boiling solvent to tempera'turesof about 200-300 C.

4. The process of producing l-phenyl-benzanthrone which consists in heating a mixture 7 of anthrone and cinnamic aldehyde to temperatures of about 200-300 C.

5. The process of'producing l-phenyl-benzanthrone which consists in heating a mixture of anthrone and cinnamic aldehyde in pres- 'ence, of an acidic condensinagent to temperatures of about 200-300? In testimony whereof we have hereunto set our hands.

WILLY TRAUTNER. BERTHOLD STEIN. "ROBERT BERLINER. 

